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Lack of Power on Detroit 60 series 500

Question:
Hey gang I figured I would repost this since the old thread died with the board upgrade. I am still having the same problem with lack of power, at least I think so, especially when 430 detroits outpull me with heavier loads. Anyway here are the car specs.
98 Freightshaker, 500/500 detroit 12.7L, 13spd, 3.73 rears, 653,000 miles
So far the parts that I have replaced are, new charge air cooler, new intake manifold gasket(both done by penn detroit). I put a new map sensor and air temp sensor in the manifold this past week. I have bought a new check valve and tank valves which I am going to put in this weekend. I also want to replace all of the fuel lines but I am going to have to put these on hold as I have to get the front rear replaced(went to speedco to get oil changed and a thrust washer split in two and a large chunk of metal to big to come out of the drain hole were found in the rear so I am having a new one put in on monday.
Here is what I noticed when pulling a hill. My turbo boost will go up to 26-27psi and stay there then it will suddenly drop to 22-23psi for a couple of seconds then go back up to 26-27psi. It will fluctuate like this until I am done pulling requiring full boost for a prolonged period other then gettin going on the flat.
I have replaced everything that would basically have anything to do with turbo pressure besides the turbo itself and the fuel lines and valves on the fuel lines. I came across a couple of posts in other forums of guys mentioning power loss and seems to be they found blockages in the check valve or in another form on the fule lines. The other problem I have is that I can run the passenger side fuel tank bone dry and still have approx. 40 gallons left in the drivers side tank.
When I had the car in at penn detroit to get the intake manifold gasket fixed they put it on the dyno and it did 412hp which they said normal is 420hp so it isn't far off just the dam thing doesn't pull in the real world. I was going to trade the dam thing in so I wouldn't have to worry bout sinking all this money into it, but now that the rear is going out I am just going to keep the thing so figuring out this power problem would be pretty nice. Hell the way things are going the car will basically be brand new here soon.

Answer:

I had a similar power problem and I to this day would never have thought it would have been electrical but it was.The main power supply off the battery to the ECM the one with the 30 amp fuse was corroded and the computer wasnt getting proper voltage or amperage. Detroit replaced link and all was fine I still dont believe it I was convinced it was a fuel problem.Just a thought. Good luck.

Answer:

Well I figured I would make an update to what I found today. Went to work on the car this am since the car won't be working till after it goes in the shop monday for the rear. Anyway, I had already bought the check the valve the other day so this morning my plans were to remove all of the fuel lines after the priM fuel filter/water seperator and replace them with new ones, and also replace the check valve. When I took the old check valve off there was a good sized piece of plastic stuck in it, the piece I managed to get out was about 1" long and 1/4" wide and there is still a piece stuck inside of it that I can't get out. Anyway I replaced the valve with the new one. The I took off the line going from the secondary filter to the back of the head. And there was a spot on the line where it was almost rubbed through, looked like it was bad enough that it may have been leaking or sucking air, I could probably have it tested to find out for sure but I just replaced it with the new hose. The only old fuel line left on the car now is the return line from the head to the tanks and the feed line from the tanks to the priM filter, I figured I would worry bought these last since they are all 1/2" lines.
Now my question is, is having the check valve clogged like that make that much of a difference in power loss? Reason I am asking is I could understand if the check valve was on the feed side of the lines before the head but since it is on the return after the head can it really make it loose that much power. My power problem definately seems to be due to lack of fuel, reason I say this is the car runs great at 1/4 to 1/2 throttle but when you start pulling a hill or for a prolonged period when full throttle and full fuel is needed is where it just seemed to not wanna run as good as what it should. Bad thing is I won't know if the car is running any better till wednesday after the front rear gets replaced, I ran the car up the road after I got everything done and it seems like it pulls through from 1600-2100 stronger then it did before, it sometimes seemed to never wanna go past 1800 rpm or it would take forever to do so. And bobtailing around you will never need full boost so it is hard to tell till I get hooked to a load.

Answer:

Hi NUTNDUN I just changed the check valve on my Detroit the other day, you can put one end of the check valve in a vise and put a wrench on it and it will come apart. There is only a pluger with a o-ring on it and a spring in it. There is not much to wear out, just the o-ring. The o-ring seats up against the body so I am just going to put a new o-ring on the one I took off and have it for a spare. Before I took the check valve off I thought it was there to keep pressure on the fuel rail and the fuel was coming from the tanks through the check valve and into the head, but like you I found out it was the opposite. I am having starting problems when I let my car get to about 1/4 tank, JLK on this site thinks I might have a split in one of my pick up tubes. I wish I knew more about how the fuel system works on a S60. What keeps the fuel pressure on the injectors? Is it that restricted flow 90 degree elbow that the check valve is mounted in. And is the check valve in the back of the head the only one in the system? If the check valve in the back of the head went bad would it let the fuel when the car was not running flow forward and drain off the fuel rail and cause hard starting after the car has sat for a few days? Well good luck with your rear end and I hope Thursday morning you smoke those 430's

Answer:

[quote="30 Coupe"] I am having starting problems when I let my car get to about 1/4 tank, JLK on this site thinks I might have a split in one of my pick up tubes..... If the check valve in the back of the head went bad would it let the fuel when the car was not running flow forward and drain off the fuel rail and cause hard starting after the car has sat for a few days?[/quote]
I had a very similiar experience with the first car I ever purchased. We knew it was hard to start when we bought it, but was told that the check valve on the back of the head was all that was wrong. Well, although that could be the problem, it wasn't. We ended up replacing a small pump located between the check valve and the main fuel pump (best as I remember). That fixed the car. I'm fairly sure it was in front of the main pump but couldn't sweat to it. As far as your mention of when you are below 1/4 tank, that car was below a 1/4 tank, but we weren't running yet, so we had no idea that it would improve if we just added fuel..lol.
Maybe some of the mechanics on this forum will pick up on my post and clear the mud out of it for ya..lol..I'm sure this isn't the first time, well second that this has happened.
Arky

Answer:

The check valve allows fuel to stay in the head when not running to maintain prime for fuel system..........................any leak allowing air into fuel system will cause hard to start problem............injector o-rings, primer pumps , fuel pumps, check valve and hoses............If unit is equipped with primer pump ,make sure pump handle is locked down..................Verifying fuel pressure will save you ppl lots of time, The restrictor fitting allows the fuel pump to maintain fuel pressure in cylinder head.............changing the restriction can and will affect fuel pressure which will cause power issues...............This info applies to most electronic engines on the market and some mechanical Caterpillar.

Answer:

Well this tuesday will be the final day for this car, I can't afford it running me into the ground anymore. I still have yet to figure out what the power problem is, more then likely only injectors, turbo, and possibly an overhaul will fix it. I am still only getting 4.7-5.0 mpg and always frustrated pulling the hills. The radiator needs replaced. So all in all I am looking anywhere between $5,000 - $15,000 to get the car running like it should and to get everything fixed, the car has actually done me fairly well considering it was my first car and with minor problems, but now it is starting to be the costly items and the car will never be worth the money I will dump into it. I do like the idea that the car would be payed off in a year and a half but I decided to go another route.
I am going to take $6,000 of the money I would dump into the freightliner and I am trading it in on a 2001 pete 379, 400,000 miles, cat ext. warranty and 7yr 750,000 mile warranty on the tranny and rears, the guy just put a new clutch and flywheel in at 380,000 miles, and also a new alternator, starter and batteries. It has a c15 550 cat with an 18 spd, interest rate on the loan is going to be 7.5% and payments are going to be between 1450.00 and 1540.00 a month, just haven't decided how short I wanna go on the loan. I have gone to a couple dealers and the pete and kw dealers I have talked to have laughed and said they wouldn't be interested in even thinking bout trading my car in. But I happened to see this pete at a freightliner dealership when I was in to get parts, asked them bout trading my car in and they are giving me $500 more then my payoff. I don't like the idea of having a loan for that long, but I think the car is worht it and will be covered under full warranty for 3 of the years that I have the loan, I will probably only take the loan out for 4 years and pay 1540 a month, aI am paying 1440.00 a month now with a car that has cost me over $6,000 in the last 2 months and still doing alright but it just keeps getting worse. Let me know how stupid ya think I am for doing it or if ya think I may actually be making a smart decision.
The guy who had the pete traded it in for a new coronado, he hauls produce from scranton pa to florida. I made a list of things for the dealer to fix before I pick it up, small things like clutch adjustment, alignment(esp considering I just put four new drives and 2 new steers on mine and a 3 axle alignment), there was a tinny grinding sound that sounded like the brake dust cover rubbing the drum and told him to take care of that, otherwise the car is spottless and pretty well loaded, it is 265" wheelbase which is the same as mine but turns a little sharper, tires are 75% virgins, brakes are 80%+, has the heavy duty driveshaft, american class interior, and the guy has alot of money in accessories like the big drop visor, bug sheild, jj brackets and single round headlights, jj fender steps with lights and he has alot of useless chicken lights which I will strip off. As long as the weight of the car is at or under what mine is I should be in good shape.

Answer:

Hiya Nutndun,
First of all, good luck with the Pete. At least it's got a real engine in it. The surging problem you describe with the varying boost sounds similar to what I've come across recently on fleet of Mack Visions with the EA7-470 engine. After a few clicks on the clock some units started to surge when pulling hills at full engine load, going to about 33 or 34 psi boost for a short period then dropping back. Normal rated boost is 29 psi max, at which point the wastegate actuator is supposed to take over and keep it trimmed at 29 psi. Because the wastegate actuator membrane started tearing it was allowing engine to overboost, inlet manifold pressure sensor reads it and trims back the fuel to about 75% or so for as long as driver has pedal to the metal. After cresting the grade you go back to part load on the engine and you get normal operation back. Seems a bit odd how the whole fleet had the same problem before any unit got past 50,000 clicks. Mack prefers its customers to do the field testing I guess??
Cheers, TankermanNZ
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